"""
综合案例演示
"""
import my_utils.str_util
from my_utils import file_util
print(my_utils.str_util.str_reverse("黑马程序员"))
print(my_utils.str_util.substr("itheima",0,4))
file_util.append_to_file("D:/bill.txt","nihaoa")
file_util.print_file_info("D:/bill.txt")